A bird's range is that geographical area in which the bird can be found over the course of a year. No two species of birds will occupy precisely the same range. If the bird is migratory, it will have a winter range and a summer, or breeding, range. One species may have wide distribution across many regions, while another species may be highly localized. For some species the breeding area and wintering grounds together constitute a broad range. The ranges of most North American birds are constantly changing.

The ranges of each of the following birds are shown on the accompanying range map. The blue areas represent the bird's winter range, the red areas its summer or breeding range, and the purple areas where a species may be found year-round.

The Barn Owl is a permanent resident in many parts of the world.

The White-headed Woodpecker is a permanent resident but occupies a very small range.

Some Golden-crowned Kinglets are permanent residents in North America. Others have a migratory range reaching from below the border in the south and Alaska in the north.

The summer range of the Yellow Warbler extends over most of North America.